<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
  var i=5;
  switch (i) {
    case 0:window.alert(i);
    break;
    case 1:window.alert(i);
    break;
    default:window.alert("Something");
  }




  var sum=0;
  for (let i = 0; i <= 100; i++) {
    sum+=i;
  }
  window.alert(sum);



  {
    let sum=0;
    let i=1;
    do {
      sum+=i;
      i++;
    }while (i <= 100);
    window.alert(sum);
  }
</script>
</body>
</html>